The present invention concerns controllers for video games and in particular, controllers which may be linked together to allow multiple active controllers to be simultaneously connected to the video game.
Video games units having controllers which allow one or two individuals to play a video game have been available for many years. Typically such units have one or two input ports. When multiple controllers are coupled to a single port, their use is typically time-division multiplexed such that each player has a distinct time slot in which the game unit responds to only that player's controller. Either the players or the video game unit determines which one of the controllers is active at any given time. Game units having multiple input ports may have more two or more simultaneously active controllers, one for each input port. These game units typically allow only one controller to be connected to each input port at any given time.
An exemplary system which allows multiple controllers to be simultaneously connected to a single input port is disclosed in U.S. Pat. No. 4,588,187 entitled PORT EXPANSION ADAPTER FOR VIDEO GAME PORT, which is hereby incorporated by reference for its teachings on video game controllers. The system described in this patent allows a fixed number of game controllers to be connected to a single port through an adapter module. The controllers are connected in parallel in a wired OR configuration so that, if multiple controllers were active, their control signals would be logically ORed together. Unless the control signals used by these controllers are conveyed on separate input signal lines to the input port, they cannot be simultaneously active. The primary purpose of adapter module, therefore, is to allow a player to use one of several different controllers without having to physically disconnect the previous controller and connect the new controller.
Game units which allow a relatively small number of simultaneously active players are acceptable for the many types of games. To date, this has been a natural limitation because of the relatively low processing power of previous video game units. As video games become more powerful, however, more sophisticated games which allow more than two or three players are being developed. In addition, multiprocessing is being implemented in video game units, allowing multiple games, each having multiple controllers, to be played simultaneously using a single game unit.
Currently, this type of connection is handled in the context of a computer network. An exemplary system of this type is disclosed in U.S. Pat. No. 4,760,527 entitled SYSTEM FOR INTERACTIVELY PLAYING POKER WITH A PLURALITY OF PLAYERS. In the system described in this patent, individual computers are interconnected via an IEEE 488 bus and communication among the computers is controlled from a central processor.